This invention relates to a recycling apparatus for obtaining oil from waste plastics.
Conventional apparatus obtain heavy oil (fuel oil A equivalent) from waste plastics (high-polymeric waste) by thermal decomposition.
This type of conventional apparatus melts solid waste plastics (such as polyethylene, polyester and vinyl chloride) at a relatively low temperature of approximately 250.degree. C. (or 70.degree. C. for vinyl chloride) in a melting tank which thermally decomposes the molten waste plastics in a thermal decomposition tank heated to approximately 400.degree. C. (or 170.degree. C. for vinyl chloride). There is obtained the desired heavy oil by cooling the gas produced by the thermal decomposition. If solid waste plastics are directly charged into the thermal decomposition tank, the waste plastics will become carbonized. While this carbonization lowers recycling efficiency, the product of carbonization is not easy to dispose of. This is the reason why the melting tank to first melt solid waste plastic is provided.
However, conventional apparatuses of the type just mentioned have involved the following problems.
First, the need for the melting tank in addition to the thermal decomposition tank makes the whole assembly more intricate, larger, more costly and difficult to maintain.
Second, the longer time required for the processing of waste plastics lowers the productivity and increases the production cost of heavy oil.
Between the upper and lower parts where thermal decomposition and melting is effected there is an intermediate transition zone where waste plastic passes from a molten state to a thermally decomposed state.
This invention solves the aforementioned problems by use of conventional technologies.
Therefore, the object of this invention is to provide a simple and compact recycling apparatus for obtaining oil from waste plastics that provides substantial cost savings and ease of maintenance while offering higher productivity and greater economy.